Pneumatic lifting jack



I 15mm OQJQSUNDSTRAND P'rmunmm Lrmm JACK Ema Dec. 24.

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OSCAR I. SUNDSTRAND, or aocxronn, rnnmors, nssrenon. or ONE-HALF ro HENRY LEE SMITH, or' omcneo,

or ROCKFORD, ILLINOIS.

,ILLINOIS, AND ONE-HALF TO' EDWARD G. PETERSON,

- PNEUMATIC LIFTING JACK.

Application filed December 24, 1921.. Serial ms. 524,883.

To all whom it may concern I Be it known that I, OSCAR J. SU'NDSTRAND, a citizen of the United States, residing at Rockford, in the county of Winnebago and State of Illinois, have invented certain new and useful Improvements in Pneumatic Lifting Jacks, of which the following is a specification. X p This invention relates to lifting jacks of the portable floor-jack type .primarily adapted for use in connection with motor vehicles for purposes well known in this art,

The chief object is to provide a generally improved lifting jack actuated by fluid pressure, such as compressed air, for raising a vehicle at any desired .point. I have aimed to construct the lifting jack in such novelmanner that it will save time, labor and cffort by reason of the fact that it may be quickly and conveniently placed in position and instantly operated simply by opening an. air supply valve to raise the vehicle and an exhaust valve to lower it. This device'is especially adapted for use in garages where it is frequently in demand. It ma also be carried on automobiles and trucks or use on the road, this being particularly desirable when the vehicle equipment w includes a motor driven air pump 01' carries compressedair forother purposes.

In furtherance of the foregoing, my invention contemplates among other things,- the following objects, namely,-the' provision of a portable fluid-actuated jack including a pressure supply'pipe extending substantially radially from the cylinder and e uip ed at its outer end with a handle, where y to enable quickplacement and removal of the jack without reaching under the vehicle; to provide a novel handle including a check valve at the air supply end- .and a quick-acting exhaust valve; to provide a shoe on the base end of the cylinder for preventing it from rolling when it is turned on. one side with its handle uppermost, which also prevents lossv of oil or lubricant from the cylinder through the vent opening located at this uppermost side; to provide an expansible packing for the piston and novel means for adjustin or expanding this packing from the exterior of the cylinder to in sure against the loss of air in the operated position; and to provide a jack rod associated, with the fluid-actuatedelement in a novel manner, permitting adjustment of such rod for lifting to difierent elevations.

Still another object is to provide a fluid-actuated novel manner thatit tical and durable for the purposes intended and may be commercially produced at a comparatively ow cost.

Other objects and attendant advantages wlll be appreciated by those familiar with this art as the invention becomes better understood by reference to the following description when considered in connection with the accompanying drawings jack constructed in such simple and will be thoroughly prac- 1 Figure 1 is a side elevation of a'portable fluid-actuated j aok embodying my invention, showing the jack in operative positionj f Flg. 2, a top view of thejack partly in seclon; e

Fig. 3, a vertical section: through the jack taken on the line 3-3 of Fig. 2

Fig. 4, a fragmentary view showing the japlk rod-partially extended from the piston ro Fig. 5, a section similar thepiston partially, elevated by fluid pressure;

Fig. 6, a fragmentary section showing the piston elevated as in Fig. 5 and the jack rod adjusted as shown in Fig; 4; Fig. 'i, a lon itudinal section through the jack showing t e piston in the elevated position, the jack rod removed and a wrench to Fig. showing I applied for ad usting the piston rod to expand the packing; Fig. .8, a cross section taken on the line 8 8 of Fig. 7 and Fig. 9, a side elevation showing the jack centrally apertured plates 14 and 15 between which is interposed an expansible packing disk 16, which at present is of an oil-proof rubber composition. These plates and the packing are clamped between the inner end of the piston rod '17 and a nut 18 plates '14 and 15. Suitable means,.such as a pin 21 fixed on the plate 15, prevents rotation of the nut 18 with respect to the plate 1 5. The foregoing construction enables expansion of the packin by adjustment from the exterior of the cy inder. That is, assumin the piston held by fluid pressure in the e evated position shown in Fig. 7, the operator may apply a wrench 22 to the milled upper end 23 of the piston rod 17 and turn such rod to tighten the nut 18. This increased com ression of the packing will expand it to e act the desired air-tight seal between the piston and cylinder wall. It will be manifest that by means of such an adjustment the packing may, when worn, .be

easily expanded to maintain the proper air seal; 7

'In order to increase the range of use of the jack I have provided an extensible jack 1 rod. The jack rod 24 at present in the form of a screw, is loosely slidable in the hollow piston 17 and equipped at its upper end with a seat 25 and a nut 26 fitting the screw. Thejack rod drops to a lowermost position in the piston rod limited by the nut 26. By adusting this nut on the screw, the latter may be raised or lowered as the case may be, to thereby increase or diminish the height to which the seat 25 will be elevated, it being noted that in each instance the length of the piston stroke or lift is the same. Coming now to the admission of fluid pressure to the cylinder for actuating the lpiston, it will be noted that my invention contemplates the provision of a combined handle and pressure-supply pipe, thereby providing an exceptionally simple, practical and desirable construction. The supply pipe 27 is threadingly engaged at its inner end in a boss 28 formed integral with and medially between the ends of the cylinder body as shown in Fig. 1, and radially. with respect thereto as shown in Fig. 2. The pipe 27 connects with a passage 29 in the cylinder body communicating with a fluid induction and eduction port 31 at the base end thereof.

The pipe 27 carries at its outer end a handle I '32 in the form of a T-pipe connection, one arm 33 of which is threadingly engaged on the pipe 27. The remaining arms 34 and 35 carry suitable pressure check and exhaust valves. The check valve 36 may be of any suitable type having a threaded nipple for attachment of hose connections. I have chamfered or beveled the end 37 of the arm 34 providing a reduced outer end to permit insertion of the valve 36 into the nozzle of an air-su ply hose. The exhaust valve in the opposlte arm 35 ma be ofany "construction, but preferably suc as will allow quick exhaust. For this purpose, I have provided slotted threaded end .2, whereby the exhaust passage may be quickly closed or opened by .rotation of the member 38, as will be observed. I

From the foregoing, it Wlll be manifest that by reason of the handle construction "which serves likewise as the fluid pressure supply pipe, the operator may not only very conveniently position the jack beneath a vehicle but having done so, thesupply and exhaust ends for the fluid pressure are unmediately at hand and ready for use as they form part of the means for locating the jack in position. Furthermore, by utilizing a relatively long rigid supply pipe as.a handle and arranging it to extend radially from the cylinder the handle may be very conveniently manipulated from its outer end to position the cylinder beneath a "ehicle. The cylinder and handle organization is also particularly desirable in that the handling and moving of the jack from place to place is expedited.

-That is, when withdrawing the jack from beneath a vehicle the operator simply grasps the outer end of the handle, and pulls upwardly and outwardly, thereby withdrawing the jack from under the vehicle, and inasmuch as the heavy cylinder is thus suspended from the handle it may be very conveniently'carried about. When not in use, the cylinder will be positioned on the floor as shown in Fig. 9, with the handle uppermost. In this o'sition, the cylinder is prevented from rolling sidewise by a shoe 43 on the base end of the cylinder diametrically opposite from the handle 27 This shoe also acts as a fulcrum when swinging the cylinder body into and out of upright position and is beveled as shown to facilitate this movement and also the sliding of the body into and out of position beneath the vehicle.

promote smooth action of the piston and insure a better air seal. A small vent opening 44 is provided to allow escape of air from above the piston when pressure is applied therebeneath. vThis'opening is positioned above the oil level when the piston is elevated and is located at the handle side of the cylinder to prevent loss of oil when the cylinder is turned on one side when not in use. The matter of placing the jack in operative position and removing'it has been described, and in. this regard, attention is directed to the combination of the handle and the air supply and exhaust connections which enables the jack lifting operation to be immediately performed after location of the jack, and on the other hand, immediate removal of the jack after release of the air.

. justment of the nut 26 to changethe eleva-' It will be noted that practically no effort on the part of the operator is required in operating this jack, other than-to simply push the jack body vinto position beneath the vehicle and to pull it out after use. Ad-

tion of the seat 25 may obviously be made very quickly and easily. Lengthwise ad- 'justment oi the packing to effect a positive seal may be effected w ithout disassembling the jack or removing any parts. The jack comprises but comparatively few parts, constructed in such simple manner as to be capable of production at a comparatively low cost and to serve very efiectually the purposes intended. By utilizing a cylinder as the jack-supporting body, and base, a very stable support is obtained.

' It is believed that the foregoing conveys a clear understanding of the objects prefaced above, and while I have illustrated but a single working embodiment it should be understood that changes might be made in -the construction and arrangement Without departing from the spirit and scope of the invention as expressed in the appended claims. I

I claim:

1.' A portable jack of the character described, comprising a cylindrical-body one end of which forms a base on which the body rests in the operative position, a piston in the cylinder having a extending from the opposite end thereof, the piston being adapted to be raised by fluid pressure in the cylinder and lowered by exhaust of said pressure, a fluid-pressure supply pipe connected to the body and disposed in a plane'at substantially right angles to the longitudinal axis of said body, a handle on the outer end of said supply pipe, and means on the body for holding it from rolling when 0- ally therefrom and equipped at its outer end with a handle, and a shoe on the base end of the cylinder diametrically opposite from cylinder is adapted to be swung by said handle from said upright operative position to a lowered horizontally disposed position with the handle upright, in which latter position the cylinder is prevented from rolling sidewise by said shoe.

said pipe, providing a fulcrum on which the 3. A portable jack of the character de- 1 scribed comprising a cylinder having a base and ahead at opposite ends and adapted to rest on its base when in the operative positiorf, a piston jack in the cylinder passing through the head and adapted to beraised by fluid pressure and lowered by exhaust thereof, an elongated handle radiating from one side of the cylinder and adapted to be manipulated for positioning the cylinder on its base and for tilting the cylinder to ahorizpntal position, and a shoe on the cylinder for preventing it from rolling sidewise when in said horizontal position with its handle uppermost. 1

' OSCAR J. SUNDSTRAND. 

